Micro-Feature Dimensional and Form Measurements with the NIST Fiber Probe on a CMM

The NIST fiber probe is a Coordinate Measuring Machine (CMM) probing system intended for diameter and form measurement of micro features and small holes. The Moore M48 CMM at NIST can measure holes down to 500 μm diameter with the Movamatic probe; the NIST fiber probe extends the range to less than 100 μm diameter. Over the last several years, we have performed numerous precision dimensional and form measurements using this probe mounted on the M48 CMM. We have measured size (diameter and thickness) and form (circularity, sphericity, straightness, flatness, conicity) on artifacts such as fiber optic ferrules, fuel injector nozzle holes, knife-edge and cylindrical apertures, ruby spheres, gage blocks, micro gears, and other micro-features on meso-scale components. We briefly describe the probing system and then present a few of the different applications we have studied, highlighting the challenges they represent and the measurement advances our probing system has offered. More importantly, these applications serve to highlight a new calibration service NIST can now offer industry — the dimensional measurement of micro-features at ultra-low forces.

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